Prepare filets using desired method per instructions and slice into large chunks.
Gently warm flatbreads in oven or microwave.
Place sliced chicken onto each flatbread and top with sliced tomato, cucumber, and red onion as desired. Top with tzatziki sauce and crumbled feta, if desired.
Tzatziki Sauce Instructions
Squeeze the grated cucumber over the sink in your hands to remove excess moisture. Place squeezed cucumber in a serving bowl.
Add yogurt, olive oil, herbs, lemon juice, garlic, and salt to the bowl. Stir to combine.
Let mixture rest for 5-10 minutes. Adjust seasoning to taste.